Piston for internal-combustion engines



Oct. 23, 1928. 1,688,403

v E. A.SPERRY PISTON FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14. 1922 5 Sheets-Sheet l (g1/wanton Oct. 23, 1928. 1,688,403

E. A. SPERRY PISTON FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14, 1922 3 Sheets-Sheet 2 Smuemoz l Mm /i 50E/FRY Uct. 23, 1928.

E. A. SPERRY PISTON FOR INTERNAL COMBUSTION ENGINES '5 sheets-sheet Filed Jan. 14, 1922 vwem fo z 7% gm /j'afmx www 1 it operates.

`Ifugitentd oct. 23,1928.

UNITED sirix'iliz'sI PA"ri-:NT JolFi'clz.

ELME A. SPERRY, OF BROOKLYN,-NEW YORK, ASSIGNOR TO SPERRY DEVELOFMENT COMPANY, OF`DOVER, DELAXVARE, '.A. CORPORATION OF DELAWARE.

PISTON FOR INTERNAL-COMBUSTION ENGINES.

v.Application filed January 14, 1922. -Serial No. 529,314.

This invention relates to pistons for .internal combustion engines and has to do with the cooling thereof. .Y The object of the invention is to devise a method and means whereby la cooling fluid may be positively circulated within the piston to transfer the heat from the'endof the piston with which the hot gases come in contact to the cooler portions thereof, and to cause thepsides of a piston thus cooled to move intermittently into closer contapt with .the adjacent wall of the cylinder with which Referring to the drawings wherein I have l5 shown what I now consider to be the preferred form of my invention: d

' Fig. 1 is a vertical cross section of a pisi ton constructed in accordance with my invention; a fragment of the cylinder alsobeing vaoshown.

Fig. 1.

Fig. 2 is asection' taken at right angles to'.

Fig. 3 is an enlargedsectional detail of the.

lower portion'of thel piston. Fig.,v4 is a section taken on Fig. 2, omitting the piston rod.

Fig. 5 is a vertical sectional view of a piston showing av modified form ofthe in- Vention Fig. 6 is a section takenon line 6-6 of Fi l f' .l

Fig. 7 is al vertical section of a piston 'illustrating a` further modification..

Fig. 8 Iis a diagrammatic view of in operation.

Fig.l 9 is a modified formof the invention.

fa piston in 10-10 of Fig. 9.` lnFigs. 1 to 4 inclusive,.the piston y 1 is shown as being hollow vand may be provided with internal bosses 2 for the wrist pin 3 which may be securedtherein by set screwsy The hub 5 of the connecting rod 6 is y mounted onI saidwrist pin 1n the usual man-l nel'.

Fig.l 5A is asdetail an expansionchamber.'

Fig.`10 is ai'sectional detail taken on linek within the; pisani i have Shown, a m11 7,-

shown at 13 maylpassbver the topfof the hubs 2 which form the supports for the pin. 3,- and down the sides of the piston normal to the wrist pin. Thus', on thesides 14, 15 4 of the piston normal to the wrist pin, chan'- 60 nels 16, 17 may extend tov the lower end of the piston as shown in Fig. y1, while on the sides 18, 19 under the en/ds of the pin, the cooling fluid chamber may bebmitted asis seen in Fig. 2, and, as shown in Fig. 4, separate channels extend down two sides of the piston.l i l' l These channels may be joined at the bottom to permit theA lo'w of liquid between them to maintain equalization of liquidl on both sides. To this end, I mayy employ a pair ofy end members 20, 21 attached lto the lower end of thepiston, one thereof being' associatedwith each of the depending channels. Any suitable method maybe employed to secure-said members in position. I have here shown said members as havingJthreaded projections 22 screwed into the piston.- Screws 23 'may also'beemployed'. Packing 25 may be employed between said members/80 connected with a passage 31 normally closed 90 by a plug 32. The cooling fluid :may be poured. into the chamber 9 through ythis tube, or it maybe yforced in while. the piston is in tla upright position -in the cylinder. In the latter case, liquid-may be injected' into the 95 chamber up to the height of the top oftube 30without running out again when` plug 32 is being inserted. Shouldit bedesirable at any' time to drain the liquid from the piston,

this may be done by removing plug 33 in the 100 passage 26. n The inner side of the piston head 34 may be provided with ribs 35. These ribs may also'be integrall with the sides of the piston andmayserve the double function of cool- Aing fins and braces for the head.

Presuming thepiston to .be partially filled,` with liquid, as for instance to the top of tubeJ-S 30, reciprocatoiy downward and upward -j' .movement of the piston will cause the liquid 1.10

to be thrown up and down. The liquid will thus be circulatedto all parts of chamber 9 and channels 16, 17. The liquid will, in this .ion in the top of the piston cavity and at the same time create av vacuum inthe bottom of the cavity.l Obviously, this would cause great resistance to proper circulation. In fact, the to of the liquid column or columns would brea up and splash about while the lower part would tend to remain fixed. With the tube 28 extending to the top of the piston and having a hole 29 at the bottom, however, a ready transfer of air lfrom the top of the bottom of the piston may take place. Thus a sudden downward thrust of the piston will readily result in a relatively upward thrust of the liquid, thevair cushion being transferred from the top of the piston cavity to the bottom.

It will, of course,1be seen that where the transfer tube 28 is filled with liquid to the level of the liquid in the cavity 9, there will be an upward thrust within the tube theoretically equal to the downward air pressure.

The friction between the tube and the liquid therein, however, is relatively much greater than in the case of the liquid in cavity 9,

so that in recality the downward air pressure in the tube is greater than the upward liquid j pressure therein. Also the tendency of the larger column to create a vacuum will aid in drawing the liquid out of the tube through the bottom.

I may, if desired, place a valve at the bottom of the tube to prevent the inflow of liquid during the upward stroke of the piston,

`but permitting the outflow of air during the downward stroke. Such a valve may comprisea collar 29 on the tube 28 and adapted during the downward stroke to be thrust upwardly against' a `stop pin 29, thus un covering the opening 29 and to be thrust downwardly during the upward stroke of the piston to cover said opening. Thus when operating, there will be practically no liquid in the tube, and therefore, no counterpressure to be overcome by the air in the,

tube, and a vacuum in the bottom will actually serve to draw air from the opening in the bottom of the tube.

I have also found that by withdrawing the air or at least a part of it from the piston, the liquid may be very readily tossed about when the air transfer tube 28 is omitted. To

be employed in the piston fortransferring the heat, I have found oil to Give satisfactory results, although obviously any other' suitable liquid may be used. e Figs. 5 and 6 illustrate a modified form of my invention.. In this form, the cavity 9 is shown as including 'the downwardly extending channels 16', 17 on the opposite sides of the piston 1; the saidchannels'being joined at the bottom by a passage 24 indicated by dotted lines. Cylindrical member 37 is shown as placed in the cavity, and may be secured in position by the engagement of flanges 38 thereon with cooperating lianges 39 on the inside wall 7 and a plate or plug 40 screwed into the portion 41 of the inside wall. A ring member' 42 secured to wall 7 by screws 43 and reaching under said plug may servey to prevent the latter from working loose when the piston is in use. An expansion chamber 24A may be connected to the cavity through channel 24.

A centrally located shaft 44 secured'at 45 to the piston head 34 and lodged in a boss 46 on plug 40 may serve as the guide rod of a plunger 47 adapted to reciprocate up and down in the cylinder 37. A large opening 48 is provided in thetop vof the cylinder 37 and numerous smal-ler openings 49 around the sides near the bottom thereof.

A sloping partition 50 may be placed between the wall 8 of the piston and the wall of the cylinder 37. As shown, this partition is formed integrally with the wall 8 and adapted to fit around the cylinder 37 when the latter is placed in position. The said partition is shownas extending around the greater part of the piston, but is omitted on the side of the channeljl by being cut off at 51. Thus, direct communication is cut off between the upper part of the cavity 9 and theV channel 17, but not between said upper wardly on all sides thereof, guided by par? tition 50 to channel 16'; through said channel and passage 24 to channel 17 upward through the latter channel and over the top of the extended portion 52 of the inside wall 7 which portion is provided to induce1 complete circulation in the. upper part of the channel, and then downwardly and through openings 49 into the lower end of cylinder 37 to follow the upward movement i of the vplunger 47. Downwardl movement of-'the plunger wil1,of course, cause a reverse movement of the liquid throughout the piston. Thus, as the piston reciprocates up and down during operation of the engine, the inertia of .the plunger will cause it to reciprocate in its cylinder to induce the aforesaid back and forth movement of the liquid. As the liquidsweeps back and forth `and circulates generally through the piston, it will extract heat from the hotter portions of the piston 'and distribute the same to the cooler portions.

The heat which the lower portion of the piston absorbs from the circulating liquid, will in turn be absorbed by the mediuml surrounding said lower portion. Thus, the

wall 53 will be cooled by the air or other medium in the open cavity 54 of the piston, while the wall 55 will transfer heat from the jacket passages 16 and 17 etc. to the adjaner.

wall 56, however, tends to take place ratherslowly owing to the high heat insulating the pressure isremoved, however, andthe cent wall 56 of the engine cylinder, whence it will be extracted by the circulating cooling-fluid in the jacket 57 in the usual man- The transferv of heat from wall to qualities of the oillm existing between the `twowalls. In order to increase the rate o f heat transfer, therefore, it is necessary to decrease the thickness of the oil film and thereby decrease its heatresistance. To aclcompllsh this Iv propose to administer side pressure' to the pistonv to squeeze out the greater lpart-of the oil and force the piston into closer relation with-the cylinder wall.` VThis is found to cause a chilling of` the wall ofthe piston on'the side which is brought closer to the cylinder. As soon as piston vassumes its normal centralized position in the cylinder, heat equalization takes place very rapidly; the Chilled portion of the ypiston wall absorbing heat from the hotter adjacent portions" and from the liqA uid within; Such pressure is' found to enhance greatly the rate of lheat transfer inv theseregions, and by applying the pressure alternately on opposite sides, the effect may While several suitable methods may be devised for applying the side pressure to the piston, I have found it convenient to employ the type of construction wherein the piston rod 58vis connected directly between the piston and the engine crank shaft 59 as indi- .cated in. Fig. 8. Presuming the crankshaft to be turning in the direction represented by the arrow 60 in Fig. 8, it will be recognized that the downward pgessureof the expanding gas on the piston coupled with the upward reactionary force `of the crank shaft will result ina side thrust of the piston' as indicated' by arrow 61. Also, during the compression stroke of the piston, the rod be-v i ing in the dotted line position 58 and press'- ing upwardly while the gases being compressed exert a downward pressure, a side thrust of the piston in the direction of arrow 62 will take place. lThese side thrusts are of great force and serve very well to A.squeeze the oil out from between the piston and cylinder walls on the side of the piston toward which the pressure is exerted.

In the form of the invention shown in Fig. 5, the cooling liquid cavity 9 may be completely filled with oil, or other liquid, and while I may employvone or more expan'sion chambers, such as disclosed'in my copending application, `Serial No. 486,181 for pistons for internal combustion engines,

'to absorb the expansion of the liquid when itbecomes heated, I prefer to accomplish this result by another method. This method comprises reducing the pressure of the liquid upon the piston when the liquid is in its normal or cold state, to a point below atmospheric pressure, so that when the liquid becomes heated its expanding pressure will not rise sufficiently above atmospheric pressure to crack the piston walls. One method by which this initial contracting power may be imparted to the liquid is by heating the piston and liquid to a predetermined degree beforev the liquid is sealed within the piston. While the piston and liquid are thus heated thechamber 9 maybe sealed. `Subsequent cooling will result in. the contracting 'effect of the liquid.

Fig. 7 'illustrates a further modification of the invention. In this form the Cavity or `chamber 9U may have its upper portion separated from" the downwardly extending. channels 16, 17, by a partition 64. Thls vthe line 69, and the space 'above evacuated,

downward thrust of the piston will cause a relative upward thrust of the liquidin the channels 16, 17". Valve 65 `will be forced open, permitting the liquid in channel 16 to enter and flood the upper part of the chamber. At the end of the downward stroke and the beginning of the upward stroke, valve 65 will be closed and valve 66 opened, while the liquid is forced into channel 17, fiowing through passage 24 (indicated by dotted lines) into channel 16.

/ throughout the entire. distance.

lof. the lateral force vis preferably at a point substantially midway between the upper and lower extremities of thesurface to be cooled, so that equal pressure will be applied To accomplish this',fthe wrist pin should be located at a point substantially midway between the upper and lower ends of the` piston, as

shown.

In Fig. 9 -I have 'showna modied' form.

of the invention. In this form I have shown a cavity9a within the upper end `of the piston la, and `a second cavity 9", within the 'cavity 9aL 'and lseparated therefrom byJ 'a partition 70. The two cavities are joined in the u per portionl of the pistcu'by an opening l inthe partition, while the lower part of cavity 9b may communicate withvthe outercavity through holes 72 in said partition. The .lower partof cavity 9 may be ,Y

closed. by av plate 7 3 secured bybolts 74 to pistonhead. Fixed on this shaft within the .l opening 71v Ihave shown a propeller 7 8.v A.

a flange 75 'on .the partition. Within the cavities I have shown a central shaft 75 bearing at 76 in plate 73. and at 77 in the pair of fixed shafts 79, 80ers also provided 1n the cavity 9b, beingsecured at 81, 82 to the platev 73, and attached to a 'yoke 88 at their u per ends.

The bottom of shaft 75" may have fixed thereon at 84' a circumferential spring bonsingi85, Coiled within said housing and se cured thereto at 86 is showna 'spring 87. The inner part of this spring may in turn be fixed as at 88 to' a ring 89. Without the Y shaft 75 I have shown a sleeve 90 having bearings at 91, 92 on the housing 85 and, yoke 83 respectively. The lower end of said sleeve vmay have an enlarged portion 93, (seelalso Fig. 4l0) positioned within the f ring 89 and provided with graduated recessesf94 within whichmaybe placed steel balls 95. When the sleeve is rotated yclockwise it will be seenv that the ,balls will be wedged against the ring 89. The ring being thus clutched will rotate with the sleeve to wind up the spring'87. A pawl 96 .carried by an arm 97 integral with plate 7 3 l may.` be provided to engage ratchet teeth 98 on the,

ring to prevent it from turning backward' when not grippedy by the clutch.`

An inertia member 99-is adapted 4to slide up and down over the sleeve 9.0 and the guide rods 79, 80. "A pin 100 fixed in member ,99 reaches into a spiral groovfej l01in the sleeve .90. The operation is as follows.: `When the to s'uch use.

I-Iaving described my invention what I piston -l isthrust' downwardly, the relative upward thrust of thel inertia member 99 will cause the sleeveto rotate, let us say, in a The balls 95 will clutch clockwise direction. ring y89 and wind up the spring 87 aswe have seen, and the pawl 96- will prevent the ring from turning backward.l `When the member 99 moves downwardly, the sleeve 90 will rotate in a counterclockwise direction, the balls 95releasing the ring 89 so.that the latter is not affected. y Thus, each upward movement of: member 99 will serve',v to wind up spring 87aA The energy thus stored in spring 87 willv cause the housing member 85 to turn clockwise, and being fixed on shaft 7 5, to cause said shaft and propeller 78 to rotate` similarly. Presuming the piston to be filled 'with oil or other liquid, such liquid will be caused to circulate upwardly through the inner cavity 9b, through opening 71 to the outer cavity 9a, and downwardly therethrough; fiowing into the inner cavity again- A through openingsx72, or, obviously, the liquid may-be caused to take the longer circuitl as lin Fig. 5 beforereentering cavity 9b; in

whichcase the diagonal partition 50 may be used.

In order to cushion the thrust of the inertia member 99 at the ends of its strokes,

"- springs 102 or other suitable means may be employed. f

It fwill, of course, be understood that the `mechanism contained in the inner cavity/9b,

including the propeller 78 may be placed in thel inner cavityv of the piston shown in Fig. 5.. In such case a morey positive circulation of the cooling oil through the lower end of the piston will take place as' indicated by the arrows in said Fig. 5.,.

In accordance with the provisionsof the patent statutes, I have herein described the principle of operation of my invention, to-

gether with the apparatus, which I now consider toy represent the best embodiment thereof,vbut I desire to have it understood that-theapparatus shown is only illustrative and that the inventioncan be carried out byother \means. Alsof, while it is designed to l use the various features and elements in the combinations andrelations described, some .115 of these may be altered 'and others 4omitted4 without interfering with the more general results outlined, and the invention @extends claim and/.desire to secure by yLetters Patent reciprocate within 'a cylinder, a chamber within saidl piston and filled with fluid, a second cylinderv in .said chamber anda plunger in said secondary cylinder for causing 4circulation of the fluid.

2. In combination, a hollow piston adapted to reciprocatewithin a cylinder, a chamber all. In combination, a piston adapted to.

for a cooling Huid adjacent .the inner walll of said piston, means associated with said chamber orcausing circulation of theuid when the pistonreciprocates for causing the iuidito iow down one` side of said piston-vv and )up the other side, and a diagonally disposed 'baille within said chamber interposed between the upstream and the downstream of said fluid.

3. In combination, a hollow piston adapted to `reciprocate within a cylinder, a chamber for-a cooling fluid adjacent the 'inner wall of said piston, means associated with said chamber for causing circulation ofthe fluid when the piston reciprocates, and means vfor directing .thel movingfl'uid down one side of the piston, across vthe 4bottom and up the other side.` v .n

4. In combination, a .hollow piston vadapted to reciprocate within a cylinder, a

wrlst pin in said piston, a chamber for a cooling fluid adjacent the inner `wall of said vpiston,means for inducing circulation of the fluid, and means for directing the moving fluid down one sideof the piston normal to 'the wrist pin axis, across the bottom and up l the other side. y

5. In combination, ahollow piston adapted j to reciprocate within a* cylinder, a wrist pin.

in said piston,ja chamber .for a cooling'iuid adjacent the inner wall of said piston, means dividing said chamber into inter-communi'- catingcompartments, said compartments being 'norma-l to the axis of the wrist pin and on opposite sides 'thereof'and a fluid impeller adapted to work withinsaid piston,

one side of said impeller being connected with): one oasaid" compartments and the other side with anotherv compartment.

6. In combination, a hollow piston adapted 'to reciprocate within a" cylinder, a wrist pin in said piston, a chamber adjacent the inner walll of said piston for a cooling fluid, means -.dividing said chamber into intercommunieating compartments, saids compartments being normal to thev axis 'of the 'wrist'. pin and on opposite sides'thereof 'and a plunger adapted to work within said piston, ^ene'side /of said .plunger being connected with one signature. v

ofjsaid compartments and the other side a 'cooling fluid, deilecting means .adapted when the fluid is in motion due to reci rocation pf the pistonv to directlthe- Huid rom one compartment to another on one side of the piston, and vmeans for directing' said fluid back` again on the other side.-

8. In combination, a hollowvpiston havin -V a chamber adjacent the inner wall thereo saidfchamber being divided into intercommunicating compartments by a diagonally disposed baie, a'cylilfder in said piston communicating at oppositeends with dile'rent compartments and an inertia'- operated plunger insaid cylinder.l x 9. In combination@l hollow piston-adapted to reciprocate within a cylinder, said piston .having a chamber for a cooling fluid adjacentthe inner wallthereof, a dia onally disposed baille within saidchamber or directing the fluidy down one side of thepiston and` means for directing said iluid up the other sideV when the piston reciprocates. 10. In an expansion engine, a cylinder, a`

vpiston adapted to reciprocate therein, said piston'having a chamber therein containing a liquid i and extending lsubstantially the entire length off-said pistoma crankshaft, ,a plston d connected to said 'shaft and to said piston 'at :1 -point midway, between the ends thereof, i v

11. In combination, a hollow piston adapted to` reciprocate within a, cyhnder,

`said -piston havin a chambeiladjacent 4'its innerf wall adap ed to contain a cooling fluid, 'means responslve to reciprocation ofv the piston for causing circulation of-.the

iuid, and an'cxpansion chamber associated with said rst mentioned chamber.

In'testimony whereof I have aiixed my 

